The 2004 International Hearing Aid Research Conference (IHCON) will be the third meeting of a biennial research conference formed by combination of two previous hearing aid research conferences, the Lake Arrowhead Conference, Issues in Advanced Hearing Aid Research, sponsored biennially by House Ear Institute (HEI) from 1990-1998 and the Hearing Aid Research and Development Conference co-sponsored biennially by the National Institute on Deafness and Other Communication Disorders (NIDCD) and the Department of Veterans' Affairs (DVA) from 1995-1997. The purpose of 2002 IHCON and the previous conferences has been to advance our knowledge and to facilitate progress in research and development through the exchange of current research findings and technical advancements related to the treatment of hearing impairment with hearing aids. A hallmark of the conferences has been their ability to draw together the disciplines and specialties essential to the advancement of hearing aid research. A primary goal of the 2004 IHCON is to build upon the strengths of the previous conferences to offer a multidisciplinary research conference that will better meet the needs of the hearing aid research and development field.